Drivers having even a minimum of experience in the operation of a motor vehicle have probably encountered situations where the use of headlights was required but where the condition requiring their use no longer existed by the time the vehicle was parked. Not infrequently, the driver fails to recall that the headlights are illuminated, the best result being an unnecessary return trip to the vehicle. More adverse results are notoriously common and involve a depleted auto battery with attendant frustration and delay. Such circumstances usually arise when an operator drives a vehicle from evening hours into daylight hours or during daylight foggy conditions. Both kinds of circumstances can at least, result in aggravation and at worst, significant cost if headlights are inadvertently left on.
One solution to this problem involves an automatic control which is usually supplied with the vehicle as original equipment. Such controls function to extinguish the headlights upon the simultaneous occurrence of two conditions, namely, de-energization of the ignition switch and the operator leaving the vehicle. Another approach to the problem involves the use of an audible signal actuated by the same co-existing conditions Both of these approaches involve an increment of added cost to the price of the vehicle and tend to be susceptible to break down and failure over the longer term. The latter approach also tends to be disruptive in quiet neighborhoods.
A warning device which may be readily adapted to any vehicle, which is low in cost and silent and effective in use would be an important development.